diff options
Diffstat (limited to 'src/VBox/Additions/linux/sharedfolders/vfsmod.h')
| -rw-r--r-- | src/VBox/Additions/linux/sharedfolders/vfsmod.h | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/src/VBox/Additions/linux/sharedfolders/vfsmod.h b/src/VBox/Additions/linux/sharedfolders/vfsmod.h new file mode 100644 index 00000000..b021dc3c --- /dev/null +++ b/src/VBox/Additions/linux/sharedfolders/vfsmod.h @@ -0,0 +1,478 @@ +/* $Id: vfsmod.h $ */ +/** @file + * vboxsf - Linux Shared Folders VFS, internal header. + */ + +/* + * Copyright (C) 2006-2020 Oracle Corporation + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, + * copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following + * conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES + * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT + * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, + * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +#ifndef GA_INCLUDED_SRC_linux_sharedfolders_vfsmod_h +#define GA_INCLUDED_SRC_linux_sharedfolders_vfsmod_h +#ifndef RT_WITHOUT_PRAGMA_ONCE +# pragma once +#endif + +#if 0 /* Enables strict checks. */ +# define RT_STRICT +# define VBOX_STRICT +#endif + +#define LOG_GROUP LOG_GROUP_SHARED_FOLDERS +#include "the-linux-kernel.h" +#include <iprt/list.h> +#include <iprt/asm.h> +#include <VBox/log.h> + +#if RTLNX_VER_MIN(2,6,0) +# include <linux/backing-dev.h> +#endif + +#include <VBox/VBoxGuestLibSharedFolders.h> +#include <VBox/VBoxGuestLibSharedFoldersInline.h> +#include <iprt/asm.h> +#include "vbsfmount.h" + + +/* + * Logging wrappers. + */ +#if 1 +# define TRACE() LogFunc(("tracepoint\n")) +# define SFLOG(aArgs) Log(aArgs) +# define SFLOGFLOW(aArgs) LogFlow(aArgs) +# define SFLOG2(aArgs) Log2(aArgs) +# define SFLOG3(aArgs) Log3(aArgs) +# define SFLOGRELBOTH(aArgs) LogRel(aArgs) +# ifdef LOG_ENABLED +# define SFLOG_ENABLED 1 +# endif +#else +# define TRACE() RTLogBackdoorPrintf("%s: tracepoint\n", __FUNCTION__) +# define SFLOG(aArgs) RTLogBackdoorPrintf aArgs +# define SFLOGFLOW(aArgs) RTLogBackdoorPrintf aArgs +# define SFLOG2(aArgs) RTLogBackdoorPrintf aArgs +# define SFLOG3(aArgs) RTLogBackdoorPrintf aArgs +# define SFLOG_ENABLED 1 +# define SFLOGRELBOTH(aArgs) do { RTLogBackdoorPrintf aArgs; printk aArgs; } while (0) +#endif + + +/* + * inode compatibility glue. + */ +#if RTLNX_VER_MAX(2,6,0) + +DECLINLINE(loff_t) i_size_read(struct inode *pInode) +{ + AssertCompile(sizeof(loff_t) == sizeof(uint64_t)); + return ASMAtomicReadU64((uint64_t volatile *)&pInode->i_size); +} + +DECLINLINE(void) i_size_write(struct inode *pInode, loff_t cbNew) +{ + AssertCompile(sizeof(pInode->i_size) == sizeof(uint64_t)); + ASMAtomicWriteU64((uint64_t volatile *)&pInode->i_size, cbNew); +} + +#endif /* < 2.6.0 */ + +#if RTLNX_VER_MAX(3,2,0) && !RTLNX_RHEL_MIN(6, 10) +DECLINLINE(void) set_nlink(struct inode *pInode, unsigned int cLinks) +{ + pInode->i_nlink = cLinks; +} +#endif + + +/* global variables */ +extern VBGLSFCLIENT g_SfClient; +extern spinlock_t g_SfHandleLock; +extern uint32_t g_uSfLastFunction; +extern uint64_t g_fSfFeatures; + +extern struct inode_operations vbsf_dir_iops; +extern struct inode_operations vbsf_lnk_iops; +extern struct inode_operations vbsf_reg_iops; +extern struct file_operations vbsf_dir_fops; +extern struct file_operations vbsf_reg_fops; +extern struct dentry_operations vbsf_dentry_ops; +extern struct address_space_operations vbsf_reg_aops; + + +/** + * VBox specific per-mount (shared folder) information. + */ +struct vbsf_super_info { + VBGLSFMAP map; + struct nls_table *nls; + /** Set if the NLS table is UTF-8. */ + bool fNlsIsUtf8; + int uid; + int gid; + int dmode; + int fmode; + int dmask; + int fmask; + /** Maximum number of pages to allow in an I/O buffer with the host. + * This applies to read and write operations. */ + uint32_t cMaxIoPages; + /** The default directory buffer size. */ + uint32_t cbDirBuf; + /** The time to live for directory entries in jiffies, zero if disabled. */ + uint32_t cJiffiesDirCacheTTL; + /** The time to live for inode information in jiffies, zero if disabled. */ + uint32_t cJiffiesInodeTTL; + /** The cache and coherency mode. */ + enum vbsf_cache_mode enmCacheMode; + /** Mount tag for VBoxService automounter. @since 6.0 */ + char szTag[32]; +#if RTLNX_VER_RANGE(2,6,0, 4,12,0) + /** The backing device info structure. */ + struct backing_dev_info bdi; +#endif + /** The mount option value for /proc/mounts. */ + int32_t msTTL; + /** The time to live for directory entries in milliseconds, for /proc/mounts. */ + int32_t msDirCacheTTL; + /** The time to live for inode information in milliseconds, for /proc/mounts. */ + int32_t msInodeTTL; +#if RTLNX_VER_RANGE(4,0,0, 4,2,0) + /** 4.0 and 4.1 are missing noop_backing_dev_info export, so take down the + * initial value so we can restore it in vbsf_done_backing_dev(). (paranoia) */ + struct backing_dev_info *bdi_org; +#endif +}; + +/* Following casts are here to prevent assignment of void * to + pointers of arbitrary type */ +#if RTLNX_VER_MAX(2,6,0) +# define VBSF_GET_SUPER_INFO(sb) ((struct vbsf_super_info *)(sb)->u.generic_sbp) +# define VBSF_SET_SUPER_INFO(sb, a_pSuperInfo) do { (sb)->u.generic_sbp = a_pSuperInfo; } while (0) +#else +# define VBSF_GET_SUPER_INFO(sb) ((struct vbsf_super_info *)(sb)->s_fs_info) +# define VBSF_SET_SUPER_INFO(sb, a_pSuperInfo) do { (sb)->s_fs_info = a_pSuperInfo;} while (0) +#endif + + +/** + * For associating inodes with host handles. + * + * This is necessary for address_space_operations::vbsf_writepage and allows + * optimizing stat, lookups and other operations on open files and directories. + */ +struct vbsf_handle { + /** List entry (head vbsf_inode_info::HandleList). */ + RTLISTNODE Entry; + /** Host file/whatever handle. */ + SHFLHANDLE hHost; + /** VBSF_HANDLE_F_XXX */ + uint32_t fFlags; + /** Reference counter. + * Close the handle and free the structure when it reaches zero. */ + uint32_t volatile cRefs; +#ifdef VBOX_STRICT + /** For strictness checks. */ + struct vbsf_inode_info *pInodeInfo; +#endif +}; + +/** @name VBSF_HANDLE_F_XXX - Handle summary flags (vbsf_handle::fFlags). + * @{ */ +#define VBSF_HANDLE_F_READ UINT32_C(0x00000001) +#define VBSF_HANDLE_F_WRITE UINT32_C(0x00000002) +#define VBSF_HANDLE_F_APPEND UINT32_C(0x00000004) +#define VBSF_HANDLE_F_FILE UINT32_C(0x00000010) +#define VBSF_HANDLE_F_DIR UINT32_C(0x00000020) +#define VBSF_HANDLE_F_ON_LIST UINT32_C(0x00000080) +#define VBSF_HANDLE_F_MAGIC_MASK UINT32_C(0xffffff00) +#define VBSF_HANDLE_F_MAGIC UINT32_C(0x75030700) /**< Maurice Ravel (1875-03-07). */ +#define VBSF_HANDLE_F_MAGIC_DEAD UINT32_C(0x19371228) +/** @} */ + + +/** + * VBox specific per-inode information. + */ +struct vbsf_inode_info { + /** Which file */ + SHFLSTRING *path; + /** Some information was changed, update data on next revalidate */ + bool force_restat; + /** The timestamp (jiffies) where the inode info was last updated. */ + unsigned long ts_up_to_date; + /** The birth time. */ + RTTIMESPEC BirthTime; + + /** @name Host modification detection stats. + * @{ */ + /** The raw modification time, for mapping invalidation purposes. */ + RTTIMESPEC ModificationTime; + /** Copy of ModificationTime from the last time we wrote to the the file. */ + RTTIMESPEC ModificationTimeAtOurLastWrite; + /** @} */ + + /** handle valid if a file was created with vbsf_create_worker until it will + * be opened with vbsf_reg_open() + * @todo r=bird: figure this one out... */ + SHFLHANDLE handle; + + /** List of open handles (struct vbsf_handle), protected by g_SfHandleLock. */ + RTLISTANCHOR HandleList; +#ifdef VBOX_STRICT + uint32_t u32Magic; +# define SF_INODE_INFO_MAGIC UINT32_C(0x18620822) /**< Claude Debussy */ +# define SF_INODE_INFO_MAGIC_DEAD UINT32_C(0x19180325) +#endif +}; + +#if RTLNX_VER_MIN(2,6,19) || defined(KERNEL_FC6) +/* FC6 kernel 2.6.18, vanilla kernel 2.6.19+ */ +# define VBSF_GET_INODE_INFO(i) ((struct vbsf_inode_info *) (i)->i_private) +# define VBSF_SET_INODE_INFO(i, sf_i) (i)->i_private = sf_i +#else +/* vanilla kernel up to 2.6.18 */ +# define VBSF_GET_INODE_INFO(i) ((struct vbsf_inode_info *) (i)->u.generic_ip) +# define VBSF_SET_INODE_INFO(i, sf_i) (i)->u.generic_ip = sf_i +#endif + +extern void vbsf_init_inode(struct inode *inode, struct vbsf_inode_info *sf_i, PSHFLFSOBJINFO info, + struct vbsf_super_info *pSuperInfo); +extern void vbsf_update_inode(struct inode *pInode, struct vbsf_inode_info *pInodeInfo, PSHFLFSOBJINFO pObjInfo, + struct vbsf_super_info *pSuperInfo, bool fInodeLocked, unsigned fSetAttrs); +extern int vbsf_inode_revalidate_worker(struct dentry *dentry, bool fForced, bool fInodeLocked); +extern int vbsf_inode_revalidate_with_handle(struct dentry *dentry, SHFLHANDLE hHostFile, bool fForced, bool fInodeLocked); +#if RTLNX_VER_MIN(2,5,18) +# if RTLNX_VER_MIN(5,12,0) +extern int vbsf_inode_getattr(struct user_namespace *ns, const struct path *path, + struct kstat *kstat, u32 request_mask, unsigned int query_flags); +# elif RTLNX_VER_MIN(4,11,0) +extern int vbsf_inode_getattr(const struct path *path, struct kstat *kstat, u32 request_mask, unsigned int query_flags); +# else +extern int vbsf_inode_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *kstat); +# endif +#else /* < 2.5.44 */ +extern int vbsf_inode_revalidate(struct dentry *dentry); +#endif /* < 2.5.44 */ +#if RTLNX_VER_MIN(5,12,0) +extern int vbsf_inode_setattr(struct user_namespace *ns, struct dentry *dentry, struct iattr *iattr); +#else +extern int vbsf_inode_setattr(struct dentry *dentry, struct iattr *iattr); +#endif + + +extern void vbsf_handle_drop_chain(struct vbsf_inode_info *pInodeInfo); +extern struct vbsf_handle *vbsf_handle_find(struct vbsf_inode_info *pInodeInfo, uint32_t fFlagsSet, uint32_t fFlagsClear); +extern uint32_t vbsf_handle_release_slow(struct vbsf_handle *pHandle, struct vbsf_super_info *pSuperInfo, + const char *pszCaller); +extern void vbsf_handle_append(struct vbsf_inode_info *pInodeInfo, struct vbsf_handle *pHandle); + +/** + * Releases a handle. + * + * @returns New reference count. + * @param pHandle The handle to release. + * @param pSuperInfo The info structure for the shared folder associated + * with the handle. + * @param pszCaller The caller name (for logging failures). + */ +DECLINLINE(uint32_t) vbsf_handle_release(struct vbsf_handle *pHandle, struct vbsf_super_info *pSuperInfo, const char *pszCaller) +{ + uint32_t cRefs; + + Assert((pHandle->fFlags & VBSF_HANDLE_F_MAGIC_MASK) == VBSF_HANDLE_F_MAGIC); + Assert(pHandle->pInodeInfo); + Assert(pHandle->pInodeInfo && pHandle->pInodeInfo->u32Magic == SF_INODE_INFO_MAGIC); + + cRefs = ASMAtomicDecU32(&pHandle->cRefs); + Assert(cRefs < _64M); + if (cRefs) + return cRefs; + return vbsf_handle_release_slow(pHandle, pSuperInfo, pszCaller); +} + + +/** + * VBox specific information for a regular file. + */ +struct vbsf_reg_info { + /** Handle tracking structure. + * @note Must be first! */ + struct vbsf_handle Handle; +}; + +uint32_t vbsf_linux_oflags_to_vbox(unsigned fLnxOpen, uint32_t *pfHandle, const char *pszCaller); + + +/** + * VBox specific information for an open directory. + */ +struct vbsf_dir_info { + /** Handle tracking structure. + * @note Must be first! */ + struct vbsf_handle Handle; + /** Semaphore protecting everything below. */ + struct semaphore Lock; + /** A magic number (VBSF_DIR_INFO_MAGIC). */ + uint32_t u32Magic; + /** Size of the buffer for directory entries. */ + uint32_t cbBuf; + /** Buffer for directory entries on the physical heap. */ + PSHFLDIRINFO pBuf; + /** Number of valid bytes in the buffer. */ + uint32_t cbValid; + /** Number of entries left in the buffer. */ + uint32_t cEntriesLeft; + /** The position of the next entry. Incremented by one for each entry. */ + loff_t offPos; + /** The next entry. */ + PSHFLDIRINFO pEntry; + /** Set if there are no more files. */ + bool fNoMoreFiles; +}; + +/** Magic number for vbsf_dir_info::u32Magic (Robert Anson Heinlein). */ +#define VBSF_DIR_INFO_MAGIC UINT32_C(0x19070707) +/** Value of vbsf_dir_info::u32Magic when freed. */ +#define VBSF_DIR_INFO_MAGIC_DEAD UINT32_C(0x19880508) + + +/** + * Sets the update-jiffies value for a dentry. + * + * This is used together with vbsf_super_info::cJiffiesDirCacheTTL to reduce + * re-validation of dentry structures while walking. + * + * This used to be living in d_time, but since 4.9.0 that seems to have become + * unfashionable and d_fsdata is now used to for this purpose. We do this all + * the way back, since d_time seems only to have been used by the file system + * specific code (at least going back to 2.4.0). + */ +DECLINLINE(void) vbsf_dentry_set_update_jiffies(struct dentry *pDirEntry, unsigned long uToSet) +{ + /*SFLOG3(("vbsf_dentry_set_update_jiffies: %p: %lx -> %#lx\n", pDirEntry, (unsigned long)pDirEntry->d_fsdata, uToSet));*/ + pDirEntry->d_fsdata = (void *)uToSet; +} + +/** + * Get the update-jiffies value for a dentry. + */ +DECLINLINE(unsigned long) vbsf_dentry_get_update_jiffies(struct dentry *pDirEntry) +{ + return (unsigned long)pDirEntry->d_fsdata; +} + +/** + * Invalidates the update TTL for the given directory entry so that it is + * revalidate the next time it is used. + * @param pDirEntry The directory entry cache entry to invalidate. + */ +DECLINLINE(void) vbsf_dentry_invalidate_ttl(struct dentry *pDirEntry) +{ + vbsf_dentry_set_update_jiffies(pDirEntry, jiffies - INT32_MAX / 2); +} + +/** + * Increase the time-to-live of @a pDirEntry and all ancestors. + * @param pDirEntry The directory entry cache entry which ancestors + * we should increase the TTL for. + */ +DECLINLINE(void) vbsf_dentry_chain_increase_ttl(struct dentry *pDirEntry) +{ +#ifdef VBOX_STRICT + struct super_block * const pSuper = pDirEntry->d_sb; +#endif + unsigned long const uToSet = jiffies; + do { + Assert(pDirEntry->d_sb == pSuper); + vbsf_dentry_set_update_jiffies(pDirEntry, uToSet); + pDirEntry = pDirEntry->d_parent; + } while (!IS_ROOT(pDirEntry)); +} + +/** + * Increase the time-to-live of all ancestors. + * @param pDirEntry The directory entry cache entry which ancestors + * we should increase the TTL for. + */ +DECLINLINE(void) vbsf_dentry_chain_increase_parent_ttl(struct dentry *pDirEntry) +{ + Assert(!pDirEntry->d_parent || pDirEntry->d_parent->d_sb == pDirEntry->d_sb); + pDirEntry = pDirEntry->d_parent; + if (pDirEntry) + vbsf_dentry_chain_increase_ttl(pDirEntry); +} + +/** Macro for getting the dentry for a struct file. */ +#if RTLNX_VER_MIN(4,6,0) +# define VBSF_GET_F_DENTRY(f) file_dentry(f) +#elif RTLNX_VER_MIN(2,6,20) +# define VBSF_GET_F_DENTRY(f) (f->f_path.dentry) +#else +# define VBSF_GET_F_DENTRY(f) (f->f_dentry) +#endif + +/** + * Macro for checking if the 'data' argument passed in via mount(2) was supplied + * by the mount.vboxsf command line utility as a page of data containing the + * vbsf_mount_info_new structure. + */ +#define VBSF_IS_MOUNT_VBOXSF_DATA(data) \ + (((struct vbsf_mount_info_new *)data)->nullchar == '\0' && \ + ((struct vbsf_mount_info_new *)data)->signature[0] == VBSF_MOUNT_SIGNATURE_BYTE_0 && \ + ((struct vbsf_mount_info_new *)data)->signature[1] == VBSF_MOUNT_SIGNATURE_BYTE_1 && \ + ((struct vbsf_mount_info_new *)data)->signature[2] == VBSF_MOUNT_SIGNATURE_BYTE_2) + +extern int vbsf_stat(const char *caller, struct vbsf_super_info *pSuperInfo, SHFLSTRING * path, PSHFLFSOBJINFO result, + int ok_to_fail); +extern int vbsf_path_from_dentry(struct vbsf_super_info *pSuperInfo, struct vbsf_inode_info *sf_i, struct dentry *dentry, + SHFLSTRING ** result, const char *caller); +extern int vbsf_nlscpy(struct vbsf_super_info *pSuperInfo, char *name, size_t name_bound_len, + const unsigned char *utf8_name, size_t utf8_len); +extern int vbsf_nls_to_shflstring(struct vbsf_super_info *pSuperInfo, const char *pszNls, PSHFLSTRING *ppString); + + +/** + * Converts Linux access permissions to VBox ones (mode & 0777). + * + * @note Currently identical. + * @sa sf_access_permissions_to_linux + */ +DECLINLINE(uint32_t) sf_access_permissions_to_vbox(int fAttr) +{ + /* Access bits should be the same: */ + AssertCompile(RTFS_UNIX_IRUSR == S_IRUSR); + AssertCompile(RTFS_UNIX_IWUSR == S_IWUSR); + AssertCompile(RTFS_UNIX_IXUSR == S_IXUSR); + AssertCompile(RTFS_UNIX_IRGRP == S_IRGRP); + AssertCompile(RTFS_UNIX_IWGRP == S_IWGRP); + AssertCompile(RTFS_UNIX_IXGRP == S_IXGRP); + AssertCompile(RTFS_UNIX_IROTH == S_IROTH); + AssertCompile(RTFS_UNIX_IWOTH == S_IWOTH); + AssertCompile(RTFS_UNIX_IXOTH == S_IXOTH); + + return fAttr & RTFS_UNIX_ALL_ACCESS_PERMS; +} + +#endif /* !GA_INCLUDED_SRC_linux_sharedfolders_vfsmod_h */ |